1. Technical Field of the Invention
The embodiments of the invention relate to planar antenna arrays and, more particularly, to the utilization of a planar antenna array to provide platform enhancements.
2. Description of Related Art
Various wireless communication systems are known today to provide links between devices, whether directly or through a network. Such communication systems range from national and/or international cellular telephone systems, the Internet, point-to-point in-home system, as well as other systems. Communication systems typically operate in accordance with one or more communication standards or protocol. For instance, wireless communication systems may operate using protocols, such as IEEE 802.11, Bluetooth™, advanced mobile phone services (AMPS), digital AMPS, global system for mobile communications (GSM), code division multiple access (CDMA), local multi-point distribution systems (LMDS), multi-channel-multi-point distribution systems (MMDS), as well as others.
For each wireless communication device to participate in wireless communications, it generally includes a built-in radio transceiver (i.e., receiver and transmitter) or is coupled to an associated radio transceiver (e.g., a station for in-home and/or in-building wireless communication networks, modem, etc.). Typically, the transceiver includes a baseband processing stage and a radio frequency (RF) stage. The baseband processing provides the conversion from data to baseband signals for transmitting and baseband signals to data for receiving, in accordance with a particular wireless communication protocol. The baseband processing stage is coupled to a RF stage (transmitter section and receiver section) that provides the conversion between the baseband signals and RF signals. The RF stage may be a direct conversion transceiver that converts directly between baseband and RF or may include one or more intermediate frequency stage(s).
Furthermore, wireless devices typically operate within certain radio frequency ranges or band established by one or more communications standards or protocols. A local oscillator generally provides a local oscillation signal that is used to mix with received RF signals or baseband signals that are to be converted to RF signals in the modulation/demodulation stage of the RF front end. A synthesizer may be used to set the frequencies to drive the local oscillator to provide the desired frequencies for mixing, in which the desired frequencies are generally based on the channel frequencies established for the particular standard or protocol.
In a typical wireless device, the RF transceiver is coupled to an antenna. In some earlier portable devices, such as cordless telephones and radios, the antenna was an elongated di-pole antenna or a loop antenna. The antenna was usually located external to the device. In more recent wireless devices, such as cellular phones, portable computers, handheld audio and/or video players, the antenna is mounted internally. For example, in notebook computers, the WiFi antenna is mounted around the display or along an edge of the computer housing. In cellular phones, the antenna is disposed along the side edge or along the top of the phone casing. Most of these antennas utilize an elongated coil or a helical coil.
Devices today that communicate short range, such as those devices that utilize 802.11 protocol or Bluetooth™ protocol, generally utilize antennas that provide omni-directional coverage so that a particular position of the devices is typically not a concern. Thus, a notebook computer utilizing one of the 802.11 protocols may be placed in a general proximity to an access point, such as a router, without regard to positioning or facing of the computer in a particular way. A headset utilizing Bluetooth protocol may be worn on a person and the associated communicating device may be placed nearby or on the person, without regard to the placement of the device or particular facing by the user. The omni-directional antenna coverage is easily obtainable using wire or coil antennas, because these devices typically use communication protocols that are within the 2-6 GHz band.
As demand for data downloads increase, newer generation devices are being developed that allow for higher data transfers. These higher data rate mobile devices will most likely use communication protocols that require a higher frequency of operation. In that instance, standard coil antennas may not provide the requisite communication linkage capability. For example, devices that utilize millimeter wave protocols in the 60+ GHz range may need to transition to an array of antennas to provide the transmission and reception capabilities. Antenna arrays allow for improved beamforming characteristics at such higher frequencies, but have the drawback in that theses arrays are typically formed on a planar substrate and may be more directional than coil type antennas. In this instance, relative positioning of the mobile device could be a concern in order to maintain a communication link with other communicating devices, if the antenna pattern generated by the planar array is restrictive.
Accordingly, there is a need to obtain larger antenna coverage pattern from an antenna, where such an antenna utilizes a planar antenna array.